Diffuse Large B-Cell Lymphoma (DLBCL) comprises 30-35% of all Non-Hodgkin lymphoma. DLBCL is biologically aggressive, but can be cured in >50% of the cases. However, up to one third of the patients develop resistance and are refractory to the treatments. The standard treatment is chemotherapy CHOP or chemotherapy+Rituxamab (R-CHOP). DLBCL can be classified into three different molecular cell-of-origin (COO) subtypes: germinal center B-cell (GCB), activated B-cell (ABC), and primary mediastinal B-cell lymphoma (PMBCL). Retrospective analysis by the Lymphoma/Leukemia molecular profiling project demonstrated that DLBCL patients with GCB subtype have better prognosis than those with ABC subtype when treated with R-CHOP, and drug candidates to improve ABC subtype prognosis are in development.
Current methods for distinguishing GCB and ABC subtypes include immunohistochemistry (IHC) and gene expression profiling. IHC and gene expression profiling technologies are time consuming, and have additional drawbacks for subtype classification. For example, gene expression technology uses frozen samples and not the formaldehyde fixed paraffin embedded tissue (FFPET) specimens that are typically collected its clinical laboratories. Nanostring Technologies (Seattle, Wash.) has developed a gene expression profiling signature that classifies DLBCL subtypes using FFPET samples, but the Nanostring platform is not widely adopted in the marketplace and it is expensive. IHC also uses FFPET samples but shows high assay variability across laboratories.